Sharp LC-50U35T Service Manual page 41

Is 5V output from pin(6) of IC1602?
YES
Are there the USB signals at input pins
of IC3301(CPU)?
YES
Check J1601/IC3303 and its peripheral
circuits.
s 5V output from pin(6) of IC1603/
IC1604?
YES
Are there the USB signals at input pins
of IC1601(USB Hub)?
YES
Are there the USB signals at input pins
of IC3303(CPU)?
YES
Check J1602/J1603/IC1601 and its
peripheral circuits.
No detection of USB devices
USB1: Side terminal
Is pin(3) of IC1602 3.3V?
NO
Check the connection of a USB cable, USB devices, and periph-
eral circuits of IC1602.
Check the USB line (between J1601 and IC3303) and its periph-
eral circuits.
[J1601 USB interface pins]
NO
pin(2/3)(USB3.0 D-/+), pin(5/6)(USB3.0 RX-/+),
pin(8/9)(USB3.0 TX-/+).
[IC3303 USB interface pins]
pin(D31/C31)(USB3.0 D-/+), pin(A32/B32)(USB3.0 RX-/+),
pin(A34/B34)(USB3.0 TX-/+).
USB2/3: Bottom terminal
Is pin(3) of IC1603/IC1604 3.3V?
NO
Check the connection of a USB cable, USB devices, and
peripheral circuits of IC1603/IC1604.
Check the USB line (between J1602 and IC1601) and its
peripheral circuits.
NO
[J1602 USB interface pins]
pin(2/3)(USB D-/+)
[IC1601 USB interface pins]
pin(15/16)(USB D-/+)
Check the USB line (between J1603 and IC1601) and its
peripheral circuits.
[J1603 USB interface pins]
pin(2/3)(USB D-/+)
[IC1601 USB interface pins]
pin(12/13)(USB D-/+)
Check J1602/J1603/IC1601 and its peripheral circuits.
Check the USB line (between IC1601 and IC3303) and its
peripheral circuits.
NO
[IC1601 USB interface pins]
pin(1/2)(USB D-/+)
[IC1601 USB interface pins]
pin(B17/A17)(USB D-/+)
6 – 19
YES
YES
LC50/58/65U35T
Check the
NO
peripheral
circuits of
IC3303.
Check the periph-
NO
eral circuits of
IC3303.